银合欢涠洲DHP—降解细菌脱毒及饲喂乳牛效果的研究

将１８头乳用后备母牛分为３组，其中Ⅲ组为对照组，喂象草，Ⅰ，Ⅱ组喂银合欢并分别以灌胃接种和接触感染方式使试牛获得涠洲ＤＨＰ－降解细菌，观察银合欢的脱毒和饲养效果。结果指出，接种后Ⅰ，Ⅱ组试牛尿中３－羟基－４（１氢）吡啶酮浓度明显降低，其中Ⅰ组各试牛最后均为零，Ⅰ，Ⅱ组试牛瘤胃液抽出后在３７℃体外培养一周，可使培养基中ＤＨＰ全部降解，由此说明涠洲ＤＨＰ－降解细菌可在试牛瘤胃中充分繁殖生长并发挥脱毒作     

含羞草素降解途径的研究

银合欢是一种速生高产豆科木本饲料,被誉为热带和亚热带地区的“奇迹树”,和“蛋白质库”。银合欢所含含羞草素〔β－Ｎ－（３－羟基－４－吡啶酮〕－α－苯丙氨酸〕及其瘤胃代谢产物３,４－ＤＨＰ〔３－羟基－４（１氢）吡啶酮〕对反刍家畜有毒。但将“涠洲瘤胃液”灌入反刍家畜瘤胃后,用银合欢饲喂反刍家畜,不但不引起中毒,而且可取得良好的饲养效果,本试验对含羞草素在“涠洲瘤胃液”脱毒细菌作用下的降解途径进行了探讨。     

木本饲料资源银合欢脱毒与开发利用

木本豆科植物银合欢嫩茎叶干物质含量达33％～36％，粗蛋白质含量占干物质22％～29％，在我国热带、南亚热带地区开发潜力很大，是我国木本蛋白质饲料的宝贵资源。但银合欢的毒性影响其开发利用，为此进行了脱毒与开发利用的研究，并取得一系列研究成果。①查明我国银合欢枝叶中含羞草素含量高达3％～4％，并引起我国肉牛、山羊和绵羊中毒。②发现能使银合欢脱毒的涠洲瘤胃液。灌注涠洲瘤胃液后，牛、羊全部采食银合欢枝叶也不中毒，肉牛平均日增重可达0．82公斤。③从涠洲瘤胃液中分离鉴定出3种脱毒细菌。经检验证实这3种细菌对含羞草素及…     

银合欢枝叶的饲用价值、毒性和微生物脱毒利用的研究

本文对热带、亚热带木本豆科饲料银合欢枝叶的饲用价值、毒性和微生物脱毒利用的技术及其效果进行了研究。试验结果表明:银合欢枝叶干物质粗蛋白质含量约为21％,有毒氨基酸含羞草素含量约为3％。含羞草素可在反刍家畜瘤胃内转变为另一毒素3-羟基-4(1氢)吡啶酮(DHP)。我国南方内陆地区反刍家畜瘤胃内不存在可使DHP降解的细菌,故采食银合欢出现中毒反应,并使日增重和饲料报酬下降。将澳大利亚DHP-降解细菌接种到我国内陆地区黄牛瘤胃内,可使黄牛取得对DHP的脱毒能力。作者发现我国广西北海市一小岛——涠洲岛的黄牛和山羊瘤胃内也存在某种DHP-降解细菌,将其接种转移到我国内陆地区乳牛瘤胃内,乳牛成功地取得了对DHP的脱毒能力。用涠洲DHP-降解细菌脱毒银合欢枝叶饲养乳牛取得了良好的饲养效果。     

仔猪浓缩饲料饲养效果研究报告

本试验分两组，每组５０头。仔猪从初生到６０日龄结束。对照组喂自配常规饲料，试验组喂基础日粮加Ｐ－５－Ａ乳猪浓缩料。结果试验组平均体重１３．８５千克，日增重２０７克，料肉比０．９７：１；对照组平均体重１２．３５千克，料肉比０．９７：１；对照组平均体重１２．３５千克，日增重１８２克，料肉比１．２７：１。平均体重，日增重差异均极显著。经济效益试验组好于对照组。说明Ｐ－５－Ａ乳猪浓缩料有推广价值。     

天农肥育牛用添加剂饲喂肉牛试验

选择年龄２～３岁，体重３００～４００千克的夏洛来杂公牛，西门塔尔杂交牛及黑白花公牛等品种牛共２０头，用天津农学院研制的“天农肥育牛用添加剂”进行了肥育试验，结果表明：试验组牛平均日增重１．２８２千克，对照组牛为１．０１２千克，试验组比对照组牛平均头日增重多０．２７千克，经ｔ经验两组牛日增重差异显著（Ｐ〈０．０５），经济收益比对照组头日净协１．９３元。     

仔猪早期断奶试验报告

选用莱芜猪经产母猪所产“大莱”二元杂交仔猪共５０窝，按３５日龄断奶２０窝、４５日龄２０窝、６０日龄断奶１０窝，分设为Ⅰ、Ⅱ、Ⅲ组，Ⅰ、Ⅱ组仔猪断奶后养至６０日龄，然后三组比较对仔猪生产性能的影响。结果，Ⅰ组６０日龄平均窝重２１３．９８千克，个体重２０．３８千克，日增重３４０克，成活率９５．５％；Ⅱ组６０日龄时平均窝重１９６．９千克，个体重１８．９７千克，日增重３１６克，成活率９２．５％；Ⅲ组６０日龄平均窝重１７９．８５千克，个体重１６．６７千克，日增重２７８克，成活率９０．６％。日增重Ⅰ组比Ⅱ组多２４克（Ｐ＜０．０５），比Ⅲ组多６２克（Ｐ＜０．０１）。仔猪纯收入Ⅰ组比Ⅱ组、Ⅲ组高３．７５元、１４．５９元。     

仔猪21日龄与28日龄断乳的研究

采用“同窝分组”法，在相同饲养条件下对１０窝１１０头仔猪进行了２１日龄断乳（１组）和２８日龄断乳（Ⅱ组）对比试验，测其各阶段发育，饲料利用率及效益，其结果：Ｉ组仔猪断乳后一周（２８日龄）体重（５．８５千克）和日增重（１７６克），分别比Ⅱ组低２２％和９２％，未增重者占１６．６％，减重者占３６．６％。Ⅱ组仔猪断乳后一周（３５日龄）未增和减重者各占６．７％。４２日龄时两组体重已很接近（Ｐ＞０．０５）。仔猪２１—４２日龄期间各用采食量：Ｉ组分别为０．７６、２．１５和３．７２千克，Ⅱ组分别为０．３２、１．２０和３．１９千克，仔猪在断乳后第２、３周来食量Ⅰ组明显高于Ⅱ组，表明Ⅰ组已进入生长补偿期。４２日．龄左右两组仔猪体重和采食量已无明显差异（Ｐ＞０．０５）。７—６０日龄采食量，Ｉ、Ⅱ组分别为２３．６和２２．２千克（Ｐ＞０．０５）。饲料转化比分别为１．３３和１．１９（Ｐ＞０．０５）。但每头仔猪饲料总成本，Ｉ组比Ⅱ组降低７％。     

β—启动剂Clenbuterol对猪肥育效果影响的研究

选用３２头三元杂交猪随机等分为４组，在对照组和Ⅰ、Ⅱ、Ⅲ组猪日粮中分别添加１、１．０、５．０和１０．０ｐｐｍ的β－启动剂Ｃｌｅｎｂｕｔｅｒｏｌ进行饲养试验。结果表明，与对照组比较，Ⅰ、Ⅱ、Ⅲ组在５０－９０千克体重阶段的增重速度分别提高了４．１２％、１０．９５％和７．９４％；单位增重耗料分别下降了２．１９％、７．０５％和５．４２％；背膘厚分别和了３．３０％、８．９１％和１０．５６％；胴体瘦肉率分别提     

饲粮中脱毒菜籽饼水平对生长猪的影响

在生长猪饲粮中加入占总量的０％，１０％，１５％，１８％和２０％的脱毒菜籽饼，并使供试五种饲粮的营养水平基本相同。经６０天试验，平均日增重１，２，３组与５组差异极显著，４组与５组差异显著，１－４组间差异不显著；饲料报酬，１组与５组差异显著，其他各组间差异不显著；每千克增重需饲料成本，以４组较低，５组较高。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein